For many years, recreational traveling has enjoyed popularity among a wide spectrum of the population. A concern for any traveler, naturally, is the need to provide for basic needs such as food and shelter. A significant portion of the hotel/motel industry caters to the traveler's need for shelter while the restaurant provides the availability of food and drink.
Despite the availability of overnight accommodations at hotels, motels, and the like, many travelers seek alternative accommodations either as a life-style preference or as a money saving measure. Also, convenient hotel/motel lodgings are not always available at target recreation sites so that alternative accommodations must be made. Here, many travelers prefer to use their own accommodations that they transport with them.
While the simplest form of portable accommodations may be the tent, many travelers find tents to be inconvenient or uncomfortable. Accordingly, many travelers opt for other portable accommodations such as tent, trailers, recreational vehicles, and the travel trailers known as fifth-wheel travel trailers.
As is known, a fifth-wheel travel trailer is, essentially, a small self contained home which may be towed to a desired location by any suitable tractor vehicle, for example, a pick-up truck. The forward portion of the travel trailer is provided with a downwardly depending hitch box and downwardly projecting kingpin. This kingpin is sized and adapted to mate with a standard fifth-wheel hitch that is mounted on the tractor vehicle. Thus, the tractor vehicle supports the travel trailer so that its forward end is elevated above the surface of travel, such as a roadway, while the rear portion of the vehicle is supported on a wheel set so that it may travel over the surface.
The substantial weight of the fifth-wheel travel trailer requires proper loading and mounting of the hitch assembly. Where the typical pick-up truck is employed as the tractor vehicle, the fifth-wheel tow bed hitch is secured in the bed of the pick-up truck above and slightly in front of the rear axle. It is important that the mounting not be located too far forward of the axle to avoid unnecessary bending moments about the axle. Moreover, it is important not to mount the hitch rearwardly of the axle otherwise the tractor vehicle will tend to rear off its front wheels resulting in loss of steering control. Where a long-bed truck is employed as the tractor vehicle, relatively few difficulties are encountered in the proper mounting of a bed hitch for a fifth-wheel trailer. Recently, though, the popularity of the short-bed pick-up truck has grown. Here, there is a decreased distance between the rear axle of the pick-up truck and the cab. In such cases, as discussed more thoroughly below, the proper mounting of the bed hitch results in inadequate clearance between the forward portion of the fifth-wheel trailer and the truck cab. In order to achieve adequate clearance, the tow hitch may be moved rearwardly in the bed, behind the rear axle. However, as noted above, this creates an undesirable and potentially dangerous towing configuration.
In my U.S. Pat. No. 5,890,728 issued Apr. 6, 1999, I disclose an extension coupling for use with trailers. This extension coupling mounts to the standard hitch box on the trailer and includes a forwardly projecting elongated arm that has a proximal end pivotally connected to the mount and a distal end that has a connecting pin. The connecting pin engages the standard tow bed hitch. A retainer assembly is secured to the arm and engages the tow hitch when the trailer is interconnected to the tractor vehicle so as to resist rotation of the arm relative to the tow hitch.
Despite the extension coupling taught in my earlier patent, there remains a need for improved extension couplings and trailer-to-tractor hitches that properly distribute the trailer load on the tractor bed, that resist undesirable pivoting at the fifth wheel hitch location, that accommodate a small degree of "roll", and that allow pivoting at the location of the trailer hitch box. The present invention addresses these needs by providing and improved fifth wheel tow bed hitch and an extension coupling that is constructed to engage this hitch.